Process of hardening, purifying, and touchening metals.



CHARLES L. LEIBY, OF KNOXVILLE, TENNESSEE, ASSIGNOR, BY DIRECT AND MESNEASSIGNMENTS, TO THE LEIBY COMPANY, OF SAME PLACE.

PROCESS OF HARDENING, PURIFYING, AND TOUGHENING METALS.

SPECIFICATION forming part of Letters Patent No. 661,406, dated November6, 1900.

Application filed December 5, 1898. Serial No. 698,343. (No specimens.)

To (all whom, it may concern:

Be it known that I, CHARLES L. LEIBY, a citizen of the United States,residing at Knoxville, in the county of Knox and State of Tennessee,have invented certain new and useful Improvements in Processes ofHardening, Purifying, and Toughening Metals, of which the following is aspecification.

The object of my said invention is to harden [o and toughen metals of anaturally soft, weak, or brittle character and remove impuritiestherefrom, whereby they are rendered capable of many uses for whichsteel is ordinarily employed; and it consists in the process of I 5treating said metals with chemicals or a chemical compound, whereby saidobject is accomplished, as will be hereinafter more fully described andclaimed.

In using the chemicals they may be combined before introduction orintroduced separately, substantially the same results being accomplishedby both methods. In speaking of the compound, therefore, it will notnecessarily be implied that the chemicals are actually mixed beforebeing introduced into the molten metal; but they are introducedsubstantially simultaneously when not mixed, nevertheless.

The main chemicals employed are potassium nitrate, a cyanid, and silica,(Si02.) I have found that good results are secured by using eight grainsof potassium nitrate, five grains of a cyanid, and sixty grains ofsilica in ten pounds of metal. Ordinarily I combine the parts in onepackage and throw it into the metal when in a molten state; but whenthey are thrown in in separate packages at the same time orsubstantially the same time the result is not materially different.

The particular kind of silica which I find 0 best adapted for thepurpose is finely-powdered flintstone, and this with saltpeter and anycyanid, as potassium cyanid or potassium ferri or ferro cyanid or amixture, comprises the compound I have ordinarily used. 5

While the proportions stated have brought good results, it will beunderstood that they may be varied somewhat and to suit the quantity ofmetal to be treated, as the above-stated proportionate amount ofcompound may not be required with larger quantities of metal.

Metals so treated, including iron, copper, aluminium, and alloys, becomeharder and tougher and are made capable of the uses stated.

Having thus fully described my said invention, what I claim as new, anddesire to secure by Letters Patent, is-

The process of hardening, purifying and toughening metals, whichconsists in reduc- 6o ing said metals to a molten state and introduc ingtherein potassium nitrate, a cyanid and powdered silica, substantiallyas set forth.

In witness whereof I have hereunto set my hand and seal at Washington,District of Co lumbia, this 3d day of December, A. D. 1898.

CHARLES L. LEIBY. [L. s.]

Witnesses:

CHARLES T. GATES, Jr., E. W. BRADFORD.

